Use time64 implementation by Michael G Schwern to extend allowed date/time range

The main benefit of this is to allow date/time values outside of the 32bit time_t
range which is very important on 32bit platforms. But there are also some other
issues that will be fixed with this, for example on macOS, mktime() will not work
for dates < 1902 despite time_t being 64bit.

In the same run this commit will also use a reentrant version of gmtime64_r that
should help in multithreaded scenarios.

Original code taken from: https://github.com/evalEmpire/y2038

1 files changed, 17 insertions, 11 deletions

diff --git a/src/xplist.c b/src/xplist.c
index e55a094..fc665ac 100644
--- a/src/xplist.c
+++ b/src/xplist.c
@@ -41,6 +41,7 @@
 
 #include "plist.h"
 #include "base64.h"
+#include "time64.h"
 
 #define XPLIST_TEXT	BAD_CAST("text")
 #define XPLIST_KEY	BAD_CAST("key")
@@ -258,12 +259,15 @@ static void node_to_xml(node_t* node, void *xml_struct)
     case PLIST_DATE:
         tag = XPLIST_DATE;
         {
-            time_t timev = (time_t)node_data->realval + MAC_EPOCH;
-            struct tm *btime = gmtime(&timev);
+            Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;
+            struct TM _btime;
+            struct TM *btime = gmtime64_r(&timev, &_btime);
             if (btime) {
                 val = (char*)malloc(24);
                 memset(val, 0, 24);
-                if (strftime(val, 24, "%Y-%m-%dT%H:%M:%SZ", btime) <= 0) {
+                struct tm _tmcopy;
+                copy_TM64_to_tm(btime, &_tmcopy);
+                if (strftime(val, 24, "%Y-%m-%dT%H:%M:%SZ", &_tmcopy) <= 0) {
                     free (val);
                     val = NULL;
                 }
@@ -346,7 +350,7 @@ static void node_to_xml(node_t* node, void *xml_struct)
     return;
 }
 
-static void parse_date(const char *strval, struct tm *btime)
+static void parse_date(const char *strval, struct TM *btime)
 {
     if (!btime) return;
     memset(btime, 0, sizeof(struct tm));
@@ -354,7 +358,12 @@ static void parse_date(const char *strval, struct tm *btime)
 #ifdef strptime
     strptime((char*)strval, "%Y-%m-%dT%H:%M:%SZ", btime);
 #else
-    sscanf(strval, "%d-%d-%dT%d:%d:%dZ", &btime->tm_year, &btime->tm_mon, &btime->tm_mday, &btime->tm_hour, &btime->tm_min, &btime->tm_sec);
+#ifdef USE_TM64
+    #define PLIST_SSCANF_FORMAT "%lld-%d-%dT%d:%d:%dZ"
+#else
+    #define PLIST_SSCANF_FORMAT "%d-%d-%dT%d:%d:%dZ"
+#endif
+    sscanf(strval, PLIST_SSCANF_FORMAT, &btime->tm_year, &btime->tm_mon, &btime->tm_mday, &btime->tm_hour, &btime->tm_min, &btime->tm_sec);
     btime->tm_year-=1900;
     btime->tm_mon--;
 #endif
@@ -453,14 +462,11 @@ static void xml_to_node(xmlNodePtr xml_node, plist_t * plist_node)
         if (!xmlStrcmp(node->name, XPLIST_DATE))
         {
             xmlChar *strval = xmlNodeGetContent(node);
-            time_t timev = 0;
+            Time64_T timev = 0;
             if (strlen((const char*)strval) >= 11) {
-                struct tm btime;
-                struct tm* tm_utc;
+                struct TM btime;
                 parse_date((const char*)strval, &btime);
-                timev = mktime(&btime);
-                tm_utc = gmtime(&timev);
-                timev -= (mktime(tm_utc) - timev);
+                timev = timegm64(&btime);
             }
             data->realval = (double)(timev - MAC_EPOCH);
             data->type = PLIST_DATE;